@ludam you can set the minimum & maximum tags for a post in ACP -> Settings -> Tags page. I don't think there is any option to set which tags a user would be able to use.
What are the advantages of using a worker in non-cluster environments?
I was having a look at the code, in the hopes of learning good practices I can use in my own projects and maybe be able to help develop nodeBB if I improve my skills a bit. While I'm familiar with workers and clustering, I fail to see what's the advantage of forking a process for a single process deployment and keep all the event handling.
Wouldn't it be more efficient, to have just a single process spawned at the beginning of the script and remove all the event handling?